A company earns $300 per year after taxes and is expected to earn the same amount of profits per year in the future. The company considers three financial plans: A with a debt ratio of 20 percent and a WACC of 15 percent; B with a debt ratio of 40 percent and a WACC of 10 percent; and C with a debt ratio of 80 percent and a WACC of 20 percent.

Which debt ratio will maximize the value of the company?